1. Field of the Invention
The present invention relates to the field of displaying technology, and in particular to a structure of a white OLED (Organic Light-Emitting Diode) device.
2. The Related Arts
An OLED is a flat panel displaying technique of extremely prosperous future and it shows excellent displaying performance and also possesses various advantages, such as being self-luminous, simple structure, being ultra-thin, fast response, wide view angle, low power consumption, and being capable of achieving flexible displaying and is thus regarded as a “dream display”. In addition, the investment of manufacturing installation is far less than that of TFT-LCDs (Thin-Film Transistor Liquid Crystal Displays) so that it is now favored by major display manufacturers and becomes the mainstream of the third-generation display devices of the field of displaying technology. Being on the eve of mass production, new techniques of OLED emerges virtually unlimitedly with the deepening of research and development thereof and thus, OLED displays are undergoing a break-through progress.
For full-colorization of OLED devices, one solution is to overlap a white organic light-emitting diode (WOLED) with a color filter (CF). Overlapping a WOLED and a CF requires no precise masking operations and high resolution can be achieved for the OLED device.
Recently, with the progress of the semiconductor technology, various light-emitting devices have been proposed. A quantum dot light-emitting diode (QD-LED) semiconductor technique is one of them. Light of arbitrary visible light wavelength (virtually all colors) can be generated and emitted by changing the size of a quantum dot of a light emission material. It is a quantum dot organic light emission device that is formed by combining together an organic material and an inorganic nanometer crystal having a high efficiency of light emission to show a novel structure and it shows technical advantages and prosperity of future applications that cannot be matched by the traditional inorganic semiconductor light-emitting diodes.
Since the QD-LED has a large number of advantages, the quantum-dot light-emitting diode has a prosperous future in various applications. The QD-LED is an inorganic quantum dot that serves as a composite material for a light emissive layer, which besides possessing the properties of small molecules and polymer materials, can lower down the severe requirement for packaging. Since a quantum dot is composed of an inorganic material, it shows better stability in moisture and oxygen than organic semiconductor of the same kind does. The quantum LED has quantum efficiency as high as 90% and can be used with a commercialized organic transporting layer to make a QD-LED device. Since white light is favorite in commercial applications and a color quantum dot gives off light that is relatively pure, the study of white QD-LED devices are attracting more and more attention.